Beyond the five broad factors, the facet-level analyses provided additional insights into the specific aspects of personality associated with greater inflammation. IL-6 was associated with different aspects of impulsivity, from the inability to resist cravings (high Impulsiveness), to difficulty staying on task (low Self-Discipline), to the tendency to make hasty decisions without careful consideration (low Deliberation). Individuals with higher IL-6 were also disorganized (low Order) and unable to strictly adhere to their own principles (low Dutifulness). For these individuals, the temptations of smoking, food, and a sedentary lifestyle may be too great to resist, despite the consequences, and this inability to maintain a healthy lifestyle may contribute to greater levels of IL-6. And indeed, we found that smoking and weight partially mediated these associations. In particular, individuals with impulsive-related personality traits tend to smoke (Terracciano et al. 2008a) and are overweight (Terracciano et al. 2009), and these behaviors, in turn, are associated with higher levels of IL-6. Finally, the negative association between activity and IL-6 is notable, as the decline in activity typically observed in older adulthood (Terracciano et al. 2005) may correspond with increases in inflammation also observed at this stage of the life course (Harris et al. 1999).
